The present invention relates to a storage system that is connected to another storage system.
A first storage system is connected to a second storage system, for example, when data stored in a first storage system is migrated to a second storage system. The technology disclosed in Patent Literature 1 (Japanese Laid-open Patent No. 2004-102374) is an example of data migration technology.
For example, as a first storage system, a storage system comprising a first controller, a plurality of (or one) first storage devices, and a first switching apparatus interposed between the first controller and the first storage devices can be considered. In this case, the constitution can be such that the first controller receives an input/output request (write request/read request) sent from a first upper-level device (for example, a host computer), and, in accordance with the received input/output request, carries out a data write and/or read to any one of the above-mentioned plurality of first storage devices via the first switching apparatus. Further, as a second storage system, a storage system comprising the same constitution as the first storage system can be considered (For components that are the same as those of the first storage system, the term “first” is re-read as “second.”)
For example, technology, which directly links first and second controllers via a leased line (for example, cable) for inter-controller communications, can be considered as one inter-storage system communications technology. There are times when another, different communications technology is desirable. Further, the interconnection of storage systems is not limited to instances of data migration; other types of cases are also possible.